Which term refers to a gradual increase in speed in a musical passage?

The term that refers to a gradual increase in speed in a musical passage is "accelerando." This term comes from the Italian word "accelerare," which means "to accelerate" or "to speed up." In musical notation, when composers want to indicate that the performers should gradually increase the tempo, they will typically use the term "accelerando."

This term serves to create a sense of excitement or intensity as the music builds. It's often used in various musical contexts, ranging from classical compositions to contemporary pieces, allowing the musicians to convey emotion and dynamics effectively.

In contrast, "decelerando" indicates a gradual decrease in speed, while "ritardando" also refers to slowing down the tempo but emphasizes a more deliberate reduction. The term "forte," on the other hand, pertains to dynamic levels in music, specifically meaning "loud," and does not relate to tempo at all. Understanding these terms and their applications is crucial for interpreting and performing music accurately.